Why is the solution length calculated using EnsembleProblem different?

New to Julia
,
1

I use EnsembleProblem to calculate 100 trajectories of a sde,why the length of every trajectories are different?

using DifferentialEquations


# Simulate SDE
function f_fn(dx, x, p, t)
    ω₀, α, γ, β = p
    dx[1] = x[2]
    dx[2] = -ω₀*x[1]-α*x[2]-γ*x[1]^2*x[2]-β*x[2]^3
end

function σ_fn(dx, x, p, t)
    dx[1] = 0
    dx[2] = sqrt(2*pi)*x[1]
end

ω₀ = 1
α = -1
γ = 0.1
β = 0.1
prob = SDEProblem(f_fn,σ_fn, [0.01, 0.01], (0.0, 60), [ω₀, α, γ, β])
ensembleprob = EnsembleProblem(prob)
sol = solve(ensembleprob, EnsembleThreads(), trajectories = 100, tspan=(0.0,60), dt=0.01)
2

Because you’re using an adaptive solver, and so it’s adapting the solution based on the new Brownian path for each solution.